I play keyboards, guitar and bass (poorly).
I'm astounded at the number of times in the last three years that I've been asked to whip out a "demo" bass line and had that accepted as the final on a recording (low-level, to be honest). In each case, that bass line has been done on one of my keyboards (mostly on a Korg Kronos).
I'm sure that backing tracks are an issue with some groups and performances, but I think it's becoming more apparent that guitar (including bass guitar) no longer drives popular music. Let that settle in for a bit.
If you're done grinding your teeth...
I have a 16-track sequencer on each of my Korgs. Truth is, I can produce a complete movie sound track on those suckers. On a more practical level, I can put together every instrumental portion of a song plus a click track and replay it via the keyboard (or, of course, a computer). In playback, I can shut down those portions that are being played by a live performer (drums, bass, etc.). That means that if we're shorthanded in rehearsal OR live, the song can come across as at least a minimal representation of what it needs to be, aside from vocals. l
Some of this comes from working pit orchestras, where a missing member happens more often the larger the orchestra is. More importantly, since timing and precision are vital for some of these productions, click tracks (at a minimum) simply happen.
In short, I'd suggest that we embrace some of the benefits of modern electronics rather than grump about it. And the second suggestion is that if we become more versatile as musicians, we'll live longer in this business.